Water-tube boiler



(No Model.)

v A., H.. 81; W. WILDMAN.

- WATER TUBE BOILER.

L Patented'Aug. 13, 1895..

No. 544,474.y

65%@ I #@@Wgz UNITED STATES PATENT OFFICE.

ANDREV VILDMAN, HENRY- WILDMAN, AND VILLIAM WILDMAN, OF

cr-I'Ic'Aeo, ILLINOIS. y

WATER-TUBE BOILER.

SPECIFICATION forming part of Letters Patent No. 544,474, dated August13, 1895.

Application led April 16 1895. Serial No. 545:967- (ND model.) l

.To all whom, it may concern:

Be it known that we, ANDREW WILDMAN, HENRY WILDMAN, and WILLIAM WILDMAN,citizens of the United States, residing at Chicago, in the county ofCook and Stato of Illinois, have invented a new anduseful lm-v provementin Water-Tube Boilers, of which the following is a specification. Y

Our invention relates to improvement in water-tube boilers or boilers ofthe class wherein the water to be converted into steam is caused tocirculate through tubes iny the path of hot products of combustion froma fire-chamber.

Our objects are to improve the construction of boilers of this classgenerally, and more especially that described and claimed in UnitedStates PatentNo. 528,352, granted October 30, 1894, to Robert Wildman,to the ends of providing a boiler of comparatively simple construction,possessing great strength and durability, and the quality in use ofgenerating steam quickly at high pressure and in large quantity with acomparatively small expense ot' fuel. To attain the ends stated, it isnecessary to provide for abundant and equal circulation ot' waterthrough the tlues; to so dispose the ilues with relation to the path ofthe products of combustion that they will be subjected to the first orgreatest heat of the latter at their eduction ends, and to providedurable and effective strengthening means for the parts exposed tosteam-pressure which will not materially retard the circulation of thecontained Water.

y To the above ends our inventionconsists in the general construction ofour improved boiler, as well as in details of construction andcombinations of parts, all as hereinafter set forth and claimed.

In the drawings, Figure lis a central vertiwhere the boiler is to beemployed to gener` ate steam at highk pressure, it would not benecessary where the boiler is to generate steam cylindrical sides of theshells.

at low pressure-as, for example, for steamheating alone. The shell Acomprises the enlarged forward Y portion A and reduced cylindricalbackward inclined portion'A2.

B is an inner casing comprising the arched -forward portion B', havingthe vertical sides J5 t and front and rear sides or flanges s s' allvupper end with an outlet-flue C2, which extends therefrom through theinner and outer shells. The opposite ends of the shell B, which areinclined,as shown, to extend parallel with each other at right anglestothe body ot' the shell, form tube-sheets q q', and fastened at theiropposite ends in the tube-sheets are the water-circulating tubes q2,which extend longitudinally through the. fiue-chan1ber C and areinclined to extend parallel with the y The space between the inner andouter shells forms a water-leg p around the tire-chamber, an annularwater-jacket p about the part B2 of the inner shell, end circulatingchambers p2 p3, and a steam-compartment p4 at the upper forward side.kThe boiler may be provided with the `upright steam-dome shown in dottedlines or the horizontal steam-dome D, the latter con- 'to the boiler,the heads n m of the latter are dishedin a'manner to render them concaveontheir inner sides, as shown. The-strength of the boiler-heads thusacquired makes it unnecessary to provide brace-rods between the heads,which is an important advantage.

and water-jacket.

Brace-rods are always an objection in water- Ilue boilers, because asthey have to pass longitudinally through flues they tend to limit thecapacity of and consequently the circulation of water through thoseflues, rendering the latter liable to burn out. Furthermore, the rodsbeing always surrounded by water and subjected to the corrosiveinfluence thereof, are apt in time to become so weakened as to beineffective. The objection urged against water-tube boilers whichinvolve the use of an inner shell, on the principle of the shell B, isthat the resistance of a large cylinder against collapsing is relativelyweak and necessitates the employment either of an inner cylinder of veryheavy material, which is not practical, or else of numerous shorttie-rods between the inner and outer shell, which make the constructionexpensive and tend to interfere with the free circulation of the water.In our construction we effectively overcome this objection, preferablyby corrugating the inner shell B, as indicated. The strength thus gainedrenders the resistance of the inner shell against collapsing under theforce ot' the steam sufficiently great to obviate all danger. In theforward portion B of the shell the corrugations may extend only over thearched portion and terminate at the side plates t, the latter beingbraced by stay-bolts Z through the water-leg. As the circulation of thewater in the water-leg is much slower than in the upper portion of theboiler, the presence of the stay-bolts is no objection, but rather anadvantage, because, besides strengthening the side walls of thefire-chamber, they form heatconductors, which aid materially in raisingthe temperature of' the water in the water-leg.

In operation water may be fed into the water-leg, as through a pipe X,whence it rises throughout the water-leg, water-jacket p', chambers p2p3, and fines q2 to the waterline at y. Fuel is fed to the fire-chamberC through the usual door z and the products of combustion rise in theforward part of the flue-chamber and, passing backward about the iiues,escape through the outlet C2. The water as it enters at X is firstheated in the water-leg by radiation from the fire-chamber wall and fromthe boltsl. As the tendency of the products of combustion is to passdirectly to the top of the chamber, the flues are subjected at their endportions adjacent to the tube-sheet q to the first and, consequently,the greatest heat. In the backward and slightly-downward movement of theproducts of combustion substantially all the available heat thereof isabsorbed through the tubes As a result of this construction the tendencyof the greater volume of water is to iiow from the water-leg backwardthrough the water-jacket to the charnberp2 and thence through the tubesto the chamber q. Thus the greatest heat is brought to bear against thewater at the eduction ends of the tubes, which is a decided advantage insteam-generation. The incline of the tubes greatly facilitatescirculation and is a safeguard against the tubes being burned. It hasbeen found that where the tubes extend horizontally and are subjected toa greater degree of heat at a certain part than at others the tendencyis for the water to become vaporized at that part and by expanding inopposite directions to so retard the circulation as to cause burning ofthe tubes. In our improved boiler this danger is overcome by incliningthe tubes and by affording the enlarged end chambers 192 p3, whichprevent crowding, in the sense that they provide a free supply at theinduction ends of the tubes and a free exit at the eduction endsthereof.

The man-heads W in the boiler-heads afford facilities for free access tothe tubes, end chambers, and water-jacket when desired.

Vhile the heat directly over the fire-box would in practice tend to keepthe tubes there free from the accumulation of soot and ashes, there isdanger that in the part of the tine-chamber back of the fire-box theywill accumulate upon the tubes, and being nonheat conducting interferewith the heating of the water at the rear end portion of the boiler. Inorder that the tubes and finechamber may be cleared from time to timefrom the accumulations of ashes and soot, we provide one or morecomparatively small tubes k through the lower part of the waterjacketand inner and outer shells to afford air-inlets to the flue-chamber. maybe closed normally by means of valves la', which seat over their outerends and are held seated preferably by means of springs k2 about thevalve-stems and confined between brackts 7c3 on the outer shell and theouter faces of the valves. The stems may be provided with handles 7a4,whereby the valves may be readily withdrawn from their seats against theresistance of the springs to open the passages and admit a gust of air.rlhe air will enter with such force as to drive the accumulated ashesand soot from the base and sides of the fine-chamber and from the Thetubes L surfaces of the tubes through the outlet C2.

By opening one or both valves from time to time the boiler-tubes willbe4 kept free from non-heat conducting accumulations.

The main advantages claimed for wateriiue boilers over those of thesmoke-flue type are, first, the more rapid production of steam dueto thewaters being subjected to the heat in comparatively small streamsinstead of in a body, and,second, on account ot` the quicker and greaterabsorption by the water of heat from the products of combustion, whichtends to economy in the use of fuel. All the features of our improvedconstruction contribute toward the obtaining of the advantages named inan enhanced degree, and furthermore toward making the boilerparticularly strong, durable, and economical to manufacture.

What we claim as new, and desire to secure by Letters Patent, is-

1. In a water-tube boiler, the combination with the fire-chamber ofinner and outer shells inclined downward in the backward direction andforming between them an inclined waterjacket, end circulating-chambers,andan upper steam chamber, the inner-shell forming the casing of alongitudinally extending flue chamber, inclined downward in the backwarddirection, which is in open communication at its lower forward endportion with the fire chamber, closed at opposite ends with tube sheetsand having an outlet at its upper rearend portion extending through thewaterjacket, and tubes in the tine-chamber inclined downward in thebackward direction and fastened at opposite ends in the tube-sheets toextend at their higher end-portions overvthe tire-chamber, substantiallyas and for the purpose set forth.

2. In a water-tube boiler, the combination with the firev chamber ofinner and outer shells forming between them a Water-leg about thefire-chamber, an inclined water-jacket and end circulating chambers, theinner-shell forming the casingofalongitudinallyinclined flue chamberwhich is in open communication at its lower forwardend-portion with thefire chamber, closed at opposite ends with tubesheets and having anoutlet at its upper rearend portion extending through the waterjacket,and inclined tubes in the flue-chamber fastened at opposite ends in thetubesheets to extend at their higher end-portions over the fire-chamber,substantially as and for the purpose set forth. Y

3. In a water-tube boiler, the combination with the re chamber of innerand outer shells forming between them an inclined waterjacket and endcirculating chambers, the inner-shell being cylindrical and providedwith annular corrugations and forming the casing of a longitudinallyinclined flue chamber which is in open communication at its lowerforward end-portion with the nre chamber, closed at opposite ends withtube-sheets and having an outlet at its upper rear-end portion extendingthrough the water-jacket, and inclined tubes in the nue-chamber fastenedat opposite ends in the tube-sheets to extend at their higherend-portions over the fire-chamber, substantially as and for the.purpose set forth.

4. In a water-tube boiler, the combination with the re chamber of innerand outer shells forming between them an inclined water-jacket and endcirculating-chambers, the inner-shell forming the casing of alongitudinally inclined Hue chamber which is in open communication atits lower forward end-portion with the fire chamber, closed at oppositeends with tube-sheets and having an outlet at its upper rear-end portionextending throu'gh'the water-jacket, and the heads of the outer shellbeing dished to present concave inner sides, and inclined tubes in theflue-,chamber fastened at opposite ends in the tubesheets to extend attheir higher endportions over the -lire-chamber, substantially as andfor the purpose set forth.

5. In a water-tube boiler, the combination of the outer shell having theenlarged forward portion and reduced and cylindrical downward inclinedrear portion and provided at opposite ends with heads having concaveinner faces, an inner shell formin-g a uechamber closed at oppositeends'with tubesheets and having the enlarged forward portion corrugatedat its upper side and shaped at its lower part to afforda tire-chamberand reduced and cylindrical downward inclined and circumferentiallycorrugated rear-portion, within and concentric with the outer shell, andhaving an outlet flue, the shells forming between them a water-leg aboutthe fire-chamber, a water-jacket, enlarged endl chambers, and asteam-,chamber in the enlarged forward portion, and tubes intheriiuechamber inclined downward in the backward direction and fastenedat opposite ends -in the tube-sheets to extend at their higherendportions over the fire-chamber, all constructed and arranged tooperate substantially as and for the purpose set forth.

' 6. In a watertube boiler, the combination with the tine-chamber, forthe passage of hot products of combustion, .and water tubes therein, andwater jacket about the said chamber of an air-inlet 'passage .extendingthrough the Water jacket to the lower part of the flue-chamber, a valvenormally closing said passage and operative to open and admit airthrough said passage to the Huechamber, substantially as and for thepurpose set forth.

7. In a water-.tube boiler, the combination with the flue-chamber, forthe passage of hot products of combustion, and water tubes therein, ofan air-inlet passage through the shell of the flue-chamber, a springseated Valve normally closing said passage, anda stem on the valveforming a handle by means of which the valve may be opened against the'resistance of the spring -to admit air to the tine-chamber,substantially as and for the purpose set forth.

ANDREW WILDMAN. HENRY WILDMAN. WILLIAM WILDMAN. In presence of- J. H.LEE, J. N. HANsoN.

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